Combination balance-rall pin and key for pianos



F. L. GEORGE.

COMBINATION BALANCE RAIL PIN AND KEY FOR PIANOS.

APPLICATION FILED OCT. 11, 1920.

1,403,401 Patented Jan. 10, 1922.

//v VENTOR FRA NK L. GEO/76E PATENT OFFICE.

FRANK L GEORGE, OF LOS ANGELES, CALIFORNIA.

COMBINATION BALANCE-RAIL PIN AND KEY FOR PIANOS.

Specification of Letters Patent.

Patented Jan. 10, 1922.

Application filed October 11, 1920. Serial No. 416,115.

To (ZZZ whom it may concern:

Be it known that I, FRANK L. GEORGE, a citizen of the United States,residing at Los Angeles, in the county of Los Angeles and tate ofCalifornia, have invented new and useful Improvements in CombinationBalance-Rail Pins and Keys for Pianos, of which the following is aspecification.

This invention relates to piano keys and the balance rail pins formingmountings for the keys.

It is the object of'the invention to provide a construction wherebypiano keys may be readily mounted upon their pins and the keys thenaccurately leveled and spaced with great ease. It is a further object ofthe invention to provide for thisleveling and spacing of the keyswithout necessitating the removal of the keys from their pins. It is astill further object of the invention to provide a construction whereinthe keys are balanced by placing the fulcrum in the center of the keyinstead of at the extreme bottom edges of the same and to also providefor strengthening the keys at their balanced points. The improvedconstruction also eliminates to a great extent the friction between keysand their pins and generally effects a saving of labor, and material ininstalling and adjusting piano keys.

In the present construction of piano keys and their balance pins greatinconvenience has been experienced due to the wearing down of the feltbushings for the keys. This wearing of the bushings has caused the keysto become unsteady upon their pins and as a result the action of thekeys has been uncertain. Furthermore, the present practice of levelingkeys by removing the latter from their pins and inserting paper washersuntil the keys are properly leveled has produced very unsatisfactoryresults and has also caused a great expenditure of time and labor.

In, the present construction the keys are properly positioned. and thewear is taken up without removing the keys from their pins and byadjusting caps which are a piano key showing the balance rail and aport-ion of the key in vertical section.

Fig. 3 is a bottom plan view of the piano key taken on the line 33 ofFig. 2.

Fig. i is an end view of the balance pin employed in the improvedconstruction.

Fig. 5 is a bottom view of the cap for the balance pin.

In the drawings is shown a balance rail 1 which may be of usualconstruction, and one of the keys mounted upon the same is shown at 2.The key 2 is bored from its un der side to form the elongated recess 3,and the forward portion of this recess is provided with a countersunkrecess 4 in the base of the same. A bore 5 of reduced diameter extendsfrom this countersunk recess as is the usual construction. The key guideisv provided with an opening 10 extending through the same in ahnementwith the portion of bore 3 in rear of the countersunk re-' cess 4, andsaid key guide is also provided with an elongated slot 11 communicatingwith the opening 10 and extending lengtlr wise of the key guide inalinement with the countersunk recess 4 The sides of this elongated slotmaybe provided with usual felt pads 12.

The balance pin upon which the key is mounted is shown in detail inFigs. 2 and 4. The pin consists of a shank 14 which is driven into thetop of the balance rail in accordance with the usual practice. Abovethis shank the pin flares outwardly from opposite sides of the shank toform the shank portion 15 of increased width. Above this portion of thepin athreaded shank 1.6 is provided, which is of approximately the samediameter as the shank end lei. In practice the pin is mounted in thebalance rail so that the shank portion 15 is positioned with itsincreased width extending transversely of the balance rail and in thedirection of the length of the key to be mounted upon said pin.

A cap 18 is screw seated upon the threaded end 16 of the balance pin,said cap comprisin a split sleeve arranged for frictional threadedengagement with the pin, and a head 19 above said sleeve and extendingover keys are properly leveled. ,pads 12become worn so that there isatend r balance pins and the keys.

the end of the balance pin. The upper surface of this head istransversely slotted as shown at 20 in order that it may be engaged by ascrew driver for adjusting the cap upon the balance pin through itsthreaded connection. t Y

For positioning the key 2 upon its balance pin the cap '18 is insertedthrough opening into the bore 8; and by then moving the key rearwardlywith relationto'its balance pin the portion of the pm is received inslot 11 and the cap 18 is moved into allnement with the countersunkrecess 4:.- The key is then lowered upon its balance :pm

until the head 19 of the cap lS is seated in the recess a; The key isnow held against "lateral displacement by engagement of padded sides ofslotll against the sides of the portion 15 of the balance pin and at the"same time the key is fulcrumed upon the balancepin through engagementof the head 19 of the cap for the balance pm against the base of recessa. The countersunk recess 4 is positioned approximately midway betweenthe upper and lower surfaces of the key 2 and the fulcrum for the key isthus provided at a point'where the movement of the key upon itsbalancepin willcause the minimum movement between the parts; As a result thefrictionalwear between the key and its balance pin is reducedmaterially.

VAfter the keys have been positioned upontheir balance pins; in order-tolevel-the same; it is only necessary to inserta'screw driver-throughbore 5 so as to engage-the V grooves 20 0f the heads of caps 18, andthe1 caps forthe balance pins may then be readily raised'and lowered uponthe'pins until the ency iof the keys to move laterally upon theirbalance pins, the pins are turned in the balance railuntil the widenedportions 15 of the, pins engage thepadded sides of slots 11 ,so asitotake up the play between the Various changes may be made without departing from the spirit of the invention as claimed. I

What is claimed is: I 7 V l. Ina piano, the combination with a bal- Whenv the felt ante rail pin, of a key fulcrumed at a point intermediateits'top and bottom faces upon said pin, and said key being provided withan opening whereby the" balance railin may be adjusted withoutremoving-the (ey from said pin.

,2. In a piano, the combination witha bal ance rail pin havin a capadjustable along said pin, of a key *ulcrumed at a point intermediateitsjto'p and bottom faces upon said cap.

Ina piano, the combination with a balance-rail pin having a cap threadedupon its end for adjustment relative to said pin, of a key fulcrumed ata point intermediate its top and bottom faces uponsaid cap.

41-. Ina piano, the combination with a balance rail pin having a capthreaded uponits end for adjustment relative tosaid pin,- of a keyfulcrumed at a point intermediate its top and bottom faces upon saidcap, said key having a bore extending through the same to its topsurface and adapted to receive a tool for engaging said cap to eifectadjustment of the latter. c 7

5. In a piano, the combination with a balance'rail pin, or" a keyfulcrumed upon said pin, said pin having a portion of increasedtrans-verse width, and said key having an elongated slot-throughwhich-said" pm portion extends, and means adapted to be engaged by asuitable tool for turning said pin to cause engagement of said portionofincreased width with the walls of said slot. I i V 7' 6. A pianobalance-rail pin comprising a shank having lateral projections on itsbody 1ntermed1ate lts ends, and a cap adjustably positioned on the upperend of said shank. v V

7.' The combination withv a'piano key provided at a point intermediateits top and bottom surfaces with a bearing and with a slot below saidbearing, of a balance raillpin having a portion of increased transversewldth arrangedon the slotted portion of the key and its upper end seatedin the bearing in said key.

In testimony whereof I have signed my; 7 name to 'th1s speclfication.

, V'FVRANKL. GEORGE.

